Coolant system filter



FIG. 1 is a front bottom perspective view of a coolant system filter showing my new design;

FIG. 2 is a rear top perspective view thereof;

FIG. 3 is a side elevational view thereof, the other side being a mirror image;

FIG. 4 is a top plan view thereof, on an enlarged scale; and,

FIG. 5 is a bottom plan view thereof, on an enlarged scale. 

The ornamental design for a coolant system filter, as shown and described. 